Typically, transducers are provided in a boat hull for measuring characteristics of the water or of the boat performance. Such characteristics include water depth, water temperature, speed through the water, as well as others. However, there have been problems with all previous methods of mounting such transducers.
One method of mounting a transducer to a boat hull such as a sonar transducer on a fiberglass or plastic boat consists of epoxying the transducer to the inside of the hull. This mounting method relies on the sonar signal to travel through the fiberglass or plastic and into the water. In order to be effective, it is important that no air bubbles, floatation materials (such as wood or plastic foam) or discontinuities be present in the hull at the installation area as well as that a solid bond of the transducer to the hull be provided. Because of this, proper installation is critical and many times is less than optimally achieved. It is also a disadvantage of this method that it is difficult to replace a faulty transducer.
A second method of mounting a transducer to a boat hull requires a hole to be drilled through the boat hull. Fairing blocks are then used to mount the transducer to the hull with the end of the transducer extending beyond the bottom of the hull underneath the fairing block. Unfortunately, the protrusion of the transducer affects the hull performance somewhat. In addition, the transducer is easily susceptible to damage in this position.
Another method of mounting a transducer to a hull is through a countersunk hole drilled in the hull in which a correspondingly shaped flush mount transducer is provided. While such a flush mount transducer does not affect hull performance and is not susceptible to damage, this installation method is labor intensive and requires skilled craftsmanship and a special countersinking tool. The transducer must also either be bonded to the hull through the hole or a sea trunk bonded to the hull through this hole and the transducer then mounted in the sea trunk with a suitable nut. By the use of the sea trunk, the transducer can be changed from the inside of the hull.
Still another method of mounting a transducer to a hull is to mount the transducer to the transom of the boat. Unfortunately, such a transducer mounting leaves the transducer susceptible to damage and if on the bottom of the boat affects hull performance.
Another problem with the transducer mounting methods discussed above is that the transducers are typically installed by riggers at a boat dealer or even by the customer. Usually, such people are not proficient at transducer installation and do not know the proper location for the transducer for a particular boat in order to achieve optimum performance in that boat.
Various types of collar structures which are mounted in boat hulls to provide through hull openings for mounting plugs and the like are disclosed in the following U.S. Pat. Nos.: 1,866,643 (Greear); 1,994,236 (Laer); 3,067,714 (Allmand); 3,400,683 (De Forest); 3,797,442 (McRae); 4,019,454 (Landwerien). An adaptor for installing marine transducers in an opening formed in the hull is also disclosed in U.S. Pat. No. 4,534,307 (Overs).
Other U.S. patents of interest which disclose the molding of an element in a mold for a boat or some other structure are disclosed in the following patents: U.S. Pat. Nos. 4,531,922 (Schutz); 3,208,466 (Vance); 1,290,448 (Whiteley, Jr.). U.S. Pat. No. 3,956,785 (Halfon) also discloses a plastic boat having a molded cleat which is fitted with countersunk bore holes.